open(QIODevice::ReadWrite) fails with QSerialPort::UnsupportedOperationError (10)

[PradeepCK]

Hello everyone,

I am new to Qt.

I am getting this error: QSerialPort::UnsupportedOperationError (10) when I try to open the serial port .

Below is the code snippet where I am seeing the error:

Header file:

    typedef struct {
        QString data;
        QSerialPort::BaudRate baudRate;
    } struct_BaudRate;

    const struct_BaudRate baudRates[7] = {
        {" "     , QSerialPort::UnknownBaud},
        {"9600"  , QSerialPort::Baud9600},
        {"19200" , QSerialPort::Baud19200},
        {"38400" , QSerialPort::Baud38400},
        {"57600" , QSerialPort::Baud57600},
        {"115200", QSerialPort::Baud115200},
        {"Custom", QSerialPort::UnknownBaud}
    };


    typedef struct {
        QString data;
        QSerialPort::DataBits dataBits;
    } struct_DataBits;

    const struct_DataBits dataBits[4] = {
        {"5", QSerialPort::Data5},
        {"6", QSerialPort::Data6},
        {"7", QSerialPort::Data7},
        {"8", QSerialPort::Data8},
    };


    typedef struct {
        QString data;
        QSerialPort::Parity Parity;
    } struct_Parity;

    const struct_Parity parity[5] = {
        {"None" , QSerialPort::NoParity},
        {"Even" , QSerialPort::EvenParity},
        {"Odd"  , QSerialPort::OddParity},
        {"Mark" , QSerialPort::MarkParity},
        {"Space", QSerialPort::SpaceParity}
    };


    typedef struct {
        QString data;
        QSerialPort::StopBits StopBits;
    } struct_StopBits;

    const struct_StopBits stopBits[3] = {
        {"1", QSerialPort::OneStop},
        {"1.5", QSerialPort::OneAndHalfStop},
        {"2", QSerialPort::TwoStop}
    };


    typedef struct {
        QString data;
        QSerialPort::FlowControl FlowControl;
    } struct_FlowControl;

    const struct_FlowControl flowControl[3] = {
        {"None", QSerialPort::NoFlowControl},
        {"RTS/CTS", QSerialPort::HardwareControl},
        {"XON/XOFF", QSerialPort::SoftwareControl}
    };


    typedef struct {
        QString Port;
        QString Description;
        QString Manufacturer;
        QString SerialNum;
        QString Location;
        QString VendorID;
        QString ProductID;
    }struct_COMDetails;

openSerialPort():

void MainWindow::openSerialPort()
{
    serialData = new QSerialPort();
    serialData->setPortName(ui->combo_commPort->currentText());
    serialData->setBaudRate(static_cast<QSerialPort::BaudRate>(baudRates[ui->combo_BaudRate->currentIndex()].baudRate));
    serialData->setDataBits(static_cast<QSerialPort::DataBits>(dataBits[ui->combo_DataBits->currentIndex()].dataBits));
    serialData->setParity(static_cast<QSerialPort::Parity>(parity[ui->combo_Parity->currentIndex()].Parity));
    serialData->setStopBits(static_cast<QSerialPort::StopBits>(stopBits[ui->combo_StopBits->currentIndex()].StopBits));
    serialData->setFlowControl(static_cast<QSerialPort::FlowControl>(flowControl[ui->combo_FlowControl->currentIndex()].FlowControl));

    if (serialData->open(QIODevice::ReadWrite)) {
        ui->button_connect->setDisabled(true);
    } else {
        QSerialPort::SerialPortError strTempError = serialData->error();
        QMessageBox::critical(this, tr("Error"), serialData->errorString());
    }

[PradeepCK]

This problem is solved now.
It was my mistake in giving incorrect index for Baud rates and other attributes.

I will be closing this topic.

[Pablo J. Rogina]

@PradeepCK said in open(QIODevice::ReadWrite) fails with QSerialPort::UnsupportedOperationError (10):

typedef struct {
QString data;
QSerialPort::BaudRate baudRate;
} struct_BaudRate;
const struct_BaudRate baudRates[7] = {
{" " , QSerialPort::UnknownBaud},
{"9600" , QSerialPort::Baud9600},
{"19200" , QSerialPort::Baud19200},
{"38400" , QSerialPort::Baud38400},
{"57600" , QSerialPort::Baud57600},
{"115200", QSerialPort::Baud115200},
{"Custom", QSerialPort::UnknownBaud}
};

Just in case, you may want to use QComboBox::itemData to avoid defining structs/arrays that hold values (i.e. baud rate) related to every item in the combo list.